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Commit 0962e800 authored by Jeremy Kerr's avatar Jeremy Kerr Committed by Benjamin Herrenschmidt
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powerpc/prom: Scan reserved-ranges node for memory reservations 

Based on benh's proposal at
https://lists.ozlabs.org/pipermail/linuxppc-dev/2012-September/101237.html

,
this change provides support for reserving memory from the
reserved-ranges node at the root of the device tree.

We just call memblock_reserve on these ranges for now.

Signed-off-by: default avatarJeremy Kerr <jk@ozlabs.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent d5d8ec89

arch/powerpc/kernel/prom.c

+35 −0
Original line number Diff line number Diff line
@@ -559,6 +559,33 @@ void __init early_init_dt_setup_initrd_arch(unsigned long start, 
}

#endif



static bool __init early_reserve_mem_dt(void)

{

	unsigned long i, len, dt_root;

	const __be32 *prop;



	dt_root = of_get_flat_dt_root();



	prop = of_get_flat_dt_prop(dt_root, "reserved-ranges", &len);



	if (!prop)

		return false;



	/* Each reserved range is an (address,size) pair, 2 cells each,

	 * totalling 4 cells per range. */

	for (i = 0; i < len / (sizeof(*prop) * 4); i++) {

		u64 base, size;



		base = of_read_number(prop + (i * 4) + 0, 2);

		size = of_read_number(prop + (i * 4) + 2, 2);



		if (size)

			memblock_reserve(base, size);

	}



	return true;

}



static void __init early_reserve_mem(void)

{

	u64 base, size;
@@ -574,6 +601,14 @@ static void __init early_reserve_mem(void) 
	self_size = initial_boot_params->totalsize;

	memblock_reserve(self_base, self_size);



	/*

	 * Try looking for reserved-regions property in the DT first; if

	 * it's present, it'll contain all of the necessary reservation

	 * info

	 */

	if (early_reserve_mem_dt())

		return;



#ifdef CONFIG_BLK_DEV_INITRD

	/* then reserve the initrd, if any */

	if (initrd_start && (initrd_end > initrd_start))